VideoVision Q&A

Q: How can I achieve 16-bit audio with VideoVision Studio?

A: There are several ways to achieve 16-bit, 44kHz audio with VideoVision Studio. Owners of the Power Macintosh 8100 series and Quadra 840AV are able to use the internal microphone from within the Sound Input dialog of their QuickTime application. Please note that the VideoVision 2.5.1 software and Apple's Sound Manager 3.1 are requried for 16-bit audio capture with the Power Macintosh 8100.

Q: When I output to Tape or TV, all I get is a black and white signal. What could be wrong?

A: Check your output settings. For NTSC overscan and underscan, there are two formats. Make sure you are on NTSC not NTSC 4.43. NTSC 4.43 is a Japanese standard of NTSC that carries the color information on a higher bandwidth.

Q: How do I get the best Image Quality out of my VideoVision Studio?

A: As a rule, noisy or grainy video compresses very poorly. You will achieve better results with Hi-8 or S-VHS source tape. Also, if you use the S-Video input for capture, you will achieve a higher quality input signal.

Q: What should I consider in setting up a drive for use with VideoVision Studio?

A: Be aware that some internal high-performance drives run very hot in Macs like the Quadra 800, 840AV and Power Macintosh 8100. Overheating drives will not perform well. An external, fan cooled drive array is recommended.

When setting up your drive, make sure that it has been properly formatted for digital video recording. Consider partitioning your hard drive into two volumes. Smaller volumes do not have to seek as far and can therefore yield better results. After turning on your hard drive or disk array, let it warm up for at least 20 minutes before you start capturing or playing back video. Periodically inspect the cables to make sure that they are firmly secure.

The other factor in choosing a drive is its sustained throughput capability. This measures how fast the drive is capable of writing data to disk. This is number is usually rated in megabytes per second. For high quality video, your drive should have a sustained throughput of 6 megabytes per second or higher. Also, when configuring a Disk Array System, it should be set for RAID level 0.

Q: How do I achieve broadcast quality with VideoVision Studio?

A: Although VideoVision Studio does 60 fields, the image quality is sharp, the video signal coming from the external patch panel does not meet the RS-170a specification for broadcast signal. What many production firms have done to achieve a broadcast ready signal is use the Component RGB Cable kit (part 637-0006-01) and use the RGB signal from the VideoVision monitor port to run into an NTSC/PAL scan converter that translates the RGB signal into a RS-170a broadcast ready signal. Also, Sony makes a Betacam SP deck, model UVW-1400, that can take the RGB signal from VideoVision directly and write it to BetaSP tape.

Q: How do I use timecode with VideoVision Studio?

A: The VideoVision hardware has no way of reading a VITC or LTC timecode track. However, there are two ways to attach timecode to a QuickTime movie. One way is to stripe a LTC SMPTE burst on one of the audio tracks. This audio track would sound like a series of modem or computer tones that could be interpreted by an LTC reader. This method is used primarily when mastering a tape in a studio to trigger external audio devices at a certain SMPTE interval. This method would not be used when attempting to generate an EDL in Premiere.

The second and more common method is to use a device like the DQ-Timecoder or Pro-VTR cable within Adobe Premiere. These devices use a serial cable from the Macintosh to the VCR that inputs Counter or SMPTE Timecode from within Premiere's batch capture option. VideoVision Studio does not have a way to regenerate timecode and output it back out to tape.

Q: What disk arrays has Radius tested, and what type of performance will I achieve?

A: Following are a series of drive recommendations and performance reports that includes our 4 gigabyte Studio Array for digital video:

StudioArray performance numbers have been officially published as:

840av Official capture rates are:

6.5 MB per second with sound OFF

6.0 MB per second VideoVision Studio sound @ 8 bit, 22 KHz

5.5 MB per second with 840av internal sound @16 bit, 44 KHz

8100/80 Official capture rates are:

5.5 MB per second with sound OFF

5.0 MB per second with sound @ 8 bit, 22 KHz

4.0 MB per second with 8100 internal sound @16 bit, 44 KHz

Power Macintosh 9150 data rates are identical to 8100.

Solutions for Quadra/Centris Processor Direct Slots:

The only currently available solution for the Quadra 950/800 PDS user is the RavenPro from Micronet. They offer a number of solutions that can sustain 5.0MB/sec with VideoVision Studio sound @ 8bit, 22kHz using Arrays or Seagate 2-HP drives.

The Quadra 950 and the Power Macintosh both have dual SCSI buses that will allow drives to be striped across the buses. The best performance Radius have achieved with these solutions is using two narrow Barracudas striped with Remus 1.2.5 SW. With this setup in the 8100, Radius has achieved a QuickTime capture and playback rate of 4.0MB/sec using VideoVision Studio sound (8b, 22kHz).

A rough rule of thumb is to expect 40-50% of raw drive transfer rates. Other Array products use slower card technologies or Hardware RAID and may be totally incompatible.

Q: How come my movies stop playing halfway through but the audio continues playing?

A: This is most often a symptom of the way your audio is set up to playback. When you make your movie in Premiere, you need to set your audio blocks to one second. This option is in the "output options" in Premiere. If you set your audio blocks to one minute or higher, you are dumping all audio into memory before your video plays and that can cause your Macintosh to freeze or the video to stop playing.

Q: When printing to tape, I don't get any audio. What is wrong?

A: The Macintosh audio is not routed to the sound output of the VideoVision External Connector panel. Use a stereo mini-jack to dual RCA cable to connect the Macintosh speaker output to the AUDIO MIX IN on the External Connector Panel. Adjust the "mix in" levels in the options dialog of the sound control panel.

A: If the monitor grays out while changing the bit depth, check if you are using Apple System 7.0.1. If you are, it is recommended you upgrade to System 7.1. There is known problem between QuickTime 1.6 and System 7.0.1 which will cause this problem with a VideoVision Studio.

Q: How do I set up Adobe Premiere for VideoVision Studio?

A: Select the Preferences option from the File menu in Premiere and verify that the scratch disk settings matches the fastest drive you are using.

Once that is set, go to the "File" menu. Select "Movie Capture".

The Menu bar will now have a menu entry marked Movie Capture. Using the Movie Capture menu select the option "Recording Settings." When you have selected "Recording Settings," make sure that the options for Post-Compress video and Record to RAM are not selected.

Select the option "Report dropped frames" this will issue a report after any capture that drops frames.

After the settings for "Recording Settings" have been made go back to the Movie Capture menu and select the menu item "Video Input." When the Video Input dialog comes up you will have three choices Compression , Image, Source, "Compression" should be selected.

With the Compression dialog box open, hold down the "Control" key while clicking on the Quality slider to open The VideoVision Studio Options settings. In the Studio Compression Options dialog is the "maintain data rate" checkbox. This feature can only be selected when adaptive compression is checked.

Checking the box "maintain data rate" turns on the data limit feature. This feature defaults to 9.9 MB/s that is the default for QuickTime. The number entered in this box will be used by VideoVision Studio to control the data rate of QuickTime capture.

The Configuration test determines what data rate a system is capable of in order to get maximum benefit from the data limit feature. With the Studio Compression Options dialog box open, and the "maintain data rate" feature enabled, click on the "Find" button. A dialog box will appear with a pop-up menu that contains the names of all mounted volumes.

The Configuration Test will be performed on the startup drive automatically. Selecting the drive used to record video will run the configuration test for that drive. There is a checkbox to adjust the test for the type of sound to be used. Select the correct sound type from the pop-up or deselect the "Adjust for sound" box if sound will not be recorded. Clicking "OK" will close the "Find" dialog, and enter the test result in the "maintain data rate" field.

When using the data limit feature, the quality slider in the QuickTime Video Settings dialog will be locked to most. This is because the system is using the number in the "maintain data rate" field to determine the quality of the QuickTime compression.

It also important to set Sound Input dialog box to "Speaker Off While Recording" or you will drop frames.

Q: In the "Options" section of Apple's Sound control panel, I can't seem to change the sound input choice. Why not?

A: The sound input group (Input 1 or Input 2) cannot be changed in the sound options dialog . This setting is changed by selecting the video input group from within a QuickTime recording application. (I.E. You have to use Video Input 1 to audio input 1 and Video Input 2 with Audio Input 2)

Q: My monitor won't sync up properly to my VideoVision Studio. I have tried the "T" and "U" key sync feature with no effect. How can I correct this?

A : With older VideoVision ROMs of v1.0 or v1.1, monitors that use a resolution of 1024x768 (commonly 20-inch monitors) were not recognized. Beyond that, the "T" and "U" keys, normally used for display configuration at startup, often fail to work properly in other situations. If you have version 1.0 or 1.1, then it is strongly suggested that you order a ROM upgrade by dialing 1-800-544-8456 and requesting upgrade part number 630-0485-01. This package includes ROM revision 1.4 and software v2.5.1. If you are unsure how to identify which ROM version you have, please request document #1240 via the Answerline's technical faxback service.

Q: When I try to capture, I get an error of --2202 or "invalid digitizing parameters." What does this mean?

A: This error occurs when the movie capture window is not on the monitor attached to VideoVision Studio.

Q: I am looking for a Macintosh to purchase for VideoVision Studio. What are the recommended CPU's?

A: There are several choices. As of March, 1995, each of the following Macintoshes are recommended and have features and benefits to consider.

An 840AV combined with the Studio array or FWB Fast and Wide disk array yields a QuickTime data rate of 6.5 Megs per Sec. (with no sound). When recording 16 bit audio the data rate drops to 4.8, still yielding more than acceptable image quality.

An 8100/80, 8100/100, and 8100/110 combined with the Studio array or FWB Fast and Wide disk array yields a QuickTime data rate of 5.0 Megs per Sec. Performance difference is roughly 4x over the Quadra 840AV when compiling with Power Macintosh native versions of Premiere or Fusion. When recording 16 bit audio the data rate drops to 4.0, still yielding more than acceptable image quality.

The Power Macintosh 9150 has the same performance as an 8100. It has 4 NuBus slots as compared to the 8100 which has 3 slots. When using a Studio array or FWB Fast and Wide disk array yields a QuickTime data rate of 5.0 Megs per Sec. Performance difference is roughly 4x over the Quadra 840AV when compiling with Power Macintosh native versions of Premiere or Fusion. When recording 16 bit audio the data rate drops to 4.0, still yielding more than acceptable image quality.

A Quadra 950 is best pared up with a PDS Array controller. The Raven Pro series is an example of a PDS based array. This system has not been tested in house but has been reported to deliver 5 Megs a second .

Video Vision Studio is a NuBus card and does not work in the PCI based PowerMacs, such as the 9500, 8500, 7500, and 7200 series of Macintoshs.

Q: I have a Quadra 840av and I get a single pixel line though the middle of the movies I make. This doesn't appear in the live video capture window. How can I get rid of it?

A: First, check the version of your VideoVision Studio Software. If it is version 1.6.2 or earlier, then you need to upgrade your version to 2.5.1 or later. With versions 1.6.2 or 1.7, check for the presence of Hardware System Update 3.0 from Apple. If installed please remove it, since it can cause this particular problem. The VideoVision software upgrade may be downloaded via modem by dialing our BBS at 408-541-6190. You may also purchase it in disk form by dialing 1-800-544-8456 and requesting part number 637-0003-01.

Q: I have an 840av and I just installed my VideoVision Studio. When I restarted my Macintosh, it bombed with a "Bus Error". I can only get my machine to start with the extensions off. What do I do?

A: Start your Macintosh with the shift key held down to turn off the extensions. Go to your extensions folder, and find the extension labeled "Apple Events Manager". Remove it from your system. This is an extension used for AppleScript, a macro-scripting language for Macintosh. Versions of this extension earlier than 1.0.3. caused a Bus Error upon start up with third-party video cards.

Q: The Premiere User's Manual states that I can print my project directly from the Construction window without rendering it. However, when I use the "Print to VideoVision Studio" option from within Premiere, I get an error of "Too Many Tracks in work area snapshot #." What am I doing wrong?

A: Printing from the construction window using the Print To VideoVision Studio export module has been shown to be unreliable. The 2.0 version of the VideoVision Software improved things to where you can output simple projects made up of simple A/B roll edits. However, in projects that involve multiple layers, pict files from multiple sources, material and media of different sizes and color pallettes, the Print To VideoVision Studio option will very often give the error above. This is because VideoVision Studio is looking for consistent field information. If you have media from multiple sources, it may or may not be field rendered for output. For the most reliable playback of Studio Compressed movie, it is best to render the movie as a QuickTime Composite or QuickTime Movie.

Q: I am doing transitions between various still pict images and they flicker and stutter. What can I do to prevent that?

A: When displaying computer graphics to an interlaced device, there are some important considerations to be made in order to avoid flickering:

As each field is drawn separately, a horizontal line that only appears on one line of one field is drawn for only 1/60th of a second. While the other field is being drawn, the first field is fading to black. Then the line is redrawn again. This causes the horizontal line to "flicker", which can induce a range of reactions in the audience, all negative.

With Radius VideoVision and the AV Macintoshes, the displaying of computer graphics to an interlaced device can be processed through a convolution filter in order to minimize flickering. Convolution involves a slight blurring of lines into the adjacent field, so that they are continuously redrawn. VideoVision's convolution is supported at 8- and 24-bit bit depths.

Radius VideoVision Studio turns convolution off when playing back unzoomed full-screen QuickTime movies in order to avoid blurring and degrading the video image quality. A side effect of this is that Macintosh graphics imported for inclusion with QuickTime movies will flicker, unless convolved manually in the project, or before importing it in the project.

This can be accomplished from within Premiere or with Photoshop. The key is the Convolution filter, which offers a convolution matrix supporting a variety of effects. The convolution matrix used by VideoVision can be duplicated by using the following matrix:

0 1 0

0 2 0

0 1 0

with a multiplier of 6.

Some users prefer using the following matrix to soften the effect:

0 1 0

1 4 1

0 1 0

with a multiplier of 8.

Additionally, stills taken from interlaced material (i.e. frames exported from full-screen QuickTime movies as PICTs) will flicker in the same manner when used in a QuickTime movie. In this case, convolution will not be as effective, and the stills must be de-interlaced instead. This, too, can be accomplished using Photoshop (Filter/Video/De-interlace) or Premiere (Clip/Field Options/De-interlace).